A new mandatory weight requirement by the national Boy Scouts of America that will take effect next January has some longtime volunteers concerned they will be left out of trips they've enjoyed with their sons for years.

According to the chart outlined in the national health and medical record form, Armstrong's weight must come down to a minimum of 239 pounds before he'll be allowed on certain "high adventure" trips that take him more than 30 minutes away from emergency care by ground transportation.

"It looks like they're trying to get the perfect person," said Armstrong, who volunteers with Troop 458 out of Chapmansboro, Tenn. "And that's not going to happen."

In Los Angeles, Joshua Godinez faces the same problem. He defined himself as "pretty obese" at 5-foot-6 and 270 pounds.

Godinez said he already sticks to non-strenuous activities. He recently took a 90-minute hike along local roads, he said.

But Godinez said he understands why some volunteers are taking exception to the new guidelines, which are discussed on the online Web site he runs that compiles scouting stories and commentary.

"I think the idea is sound," he said. "I don't know if people were ready for them to just drop it into the program."

According to the BSA chart, which it says is taken directly from federal health guidelines, Godinez needs to weigh a maximum of 201 pounds before going on a "high adventure" trip with his 17-year-old son. The recommended weight for his height is between 118 and 167 pounds.

"High adventure" is a term used to describe activities such as long treks that snake through back country.

According to an FAQ sheet from the BSA regarding health and medical records, the height/weight requirements would not prohibit overweight volunteers at most of the BSA resident camps, which are reachable by car and Cub Scout programs, which are, by nature, not strenuous because of the young age of the boys involved.

"This was a decision made by the health and safety committee," BSA national spokesman Deron Smith said. "I think that the reason behind this, this is just part of the ongoing effort of the Boy Scouts to insure they are constantly improving the safety" of scouts and their leaders.

"The goal of these policies is certainly not to restrict anyone from volunteering or participating in the scouting program," he said."

"For high adventure activities for which medical care may be delayed, restrictions based on standardized height/weight ratios are now mandatory," according to the FAQ.

A medical evaluation by a doctor is now also required annually for trips lasting longer than 72 consecutive hours.

Will Boy Scouts Lose Volunteers?

Armstrong said his weight has only been a problem when he tried to sign up to attend the BSA's Florida Sea Base with his youngest son Matthew, 8, a Wolf Scout. The Sea Base is a "high adventure" camp that offers ocean activities.

"I didn't know until midway that there was a weight requirement," he said.

Armstrong said he lost 40 pounds and passed a doctor-administered physical and completed a swim test, but it wasn't enough to allow him on the June 15 trip as he was still too heavy for some of the ladders at the facility.

Armstrong said he's concerned that enforcement of this new policy will mean fewer volunteers, which are hard enough to find as it is.

"It takes a heck of a person to do this," he said.

Commenters on Godinez's Web site, www.boyandgirlscouts.com, had the same concerns.

"This is nuts," one poster wrote. "Guidelines are welcome, not mandatory policy. Risk and ability to participate should be a matter between the boy/parent and trained medical staff, not an arbitrary table."

Both Armstrong and Godinez said they are trying to lose weight, a battle they've been fighting for years.

Armstrong said he's cut out sodas and sweet tea. But he said he hasn't weighed 239 pounds, his maximum weight for participation in high adventure activities, since "probably when I was a young guy."

The national Boy Scout destinations, such as the Florida Sea Base, have always had these standards, Smith said. According to the FAQ, local councils will be able to impose additional requirements on top of the national policy, depending on the activity in their region.

"We want to note that these policies do not restrict a person's ability to volunteer in the scouting program and are not meant to make it difficult to participate in scouting activities; rather, they are meant to ensure the health and safety of those who participate in high adventure activities," Smith said in an e-mailed statement to ABCNews.com. "Therefore, we do not expect it will greatly impact many volunteers or leaders."

Armstrong said he was concerned that the new requirements would preclude him from teaching archery next year, something he's done for years. The day camp, he believes, is more than 30 minutes away from a medical facility.

He's also now questioning whether, under the new requirement, he won't be able to help his older son, 16, complete his Eagle Scout project, which involves pouring concrete to improve a school's baseball batting cage.

But Hugh Travis, scout executive of the Middle Tennessee Council, said Armstrong would not be prevented from participating in non-high adventure activities locally and that while there are changes, height and weight requirements are nothing new for the Boy Scouts.

"The Boy Scouts are concerned about childhood and adult obesity," he said. "The primary concern is for the health and safety and welfare of the scouts and the adult leaders."

When asked what affect the new requirements would have on his volunteers, Travis said he doesn't expect much of any. Out of about 12,000 volunteers in the Middle Tennessee Council, he said, only Armstrong has complained.